With conventional near-field data communication devices using radio waves, power consumption and size of the devices tend to be relatively large when utilizing wireless communication. Wireless communication through the transmission of electromagnetic signals through air also has other drawbacks such as the potential interference by stray signals and difficulties in incorporating the necessary transmission and reception circuits into a device of a size that can be comfortably worn by the user.
One application in particular is a hearing aid system utilizing two or more components worn by a user at different locations over the user's body. During operation, it is generally desirable that one or more communication links be established between these components using wireless technology. Although interconnecting these components by wires or cables is possible, it may be undesirable to have wires passing along different parts of the body. Moreover, for certain devices which may be worn within the user's mouth, a wired device is generally undesirable.
Certain methods have been previously utilized for passing communication signals along or through the body of the user to enable the passing of data between different components. One method utilized an electrostatic field induced in a human body to reduce power consumption and by transferring high frequency modulated signals via the user's body and an earth ground. However, because ground is utilized as part of the signal path, the size of the transmitter and receiver may be particularly small to improve their wearability by the user but the distance traveled by the communications signals becomes particularly shortened.
Yet other methods may utilize the transfer of signals between separate devices using both transmission through an electric field induced over the user's body in combination with signal transmission through the air. However, this and similar methods require the use of signal transmission through an induced electric field and ground or still require the use of transmission through the air with its resultant power consumption and device form factors.
Accordingly, there is a need for near-field data communication devices and methods which operate with reduced power consumption, have a form factor which is suitably small for patient comfort, and which is able to communicate with devices configured for intra-oral placement and use.